Publications

the functional receptor for insect ecdysteroid hormones is a heterodimer consisting of two nuclear hormone receptors, ecdysteroid receptor (ecr) and the retinoid x receptor homologue ultraspiracle (usp). although ecdysone is commonly thought to be a hormone precursor and 20-hydroxyecdysone (20e), the physiologically active steroid, little is known about the relative activity of ecdysteroids in various arthropods. as a step toward characterization of potential differential ligand recognition, we ...

insights into the venom composition of the ectoparasitoid wasp nasonia vitripennis from bioinformatic and proteomic studies.

with the nasonia vitripennis genome sequences available, we attempted to determine the proteins present in venom by two different approaches. first, we searched for the transcripts of venom proteins by a bioinformatic approach using amino acid sequences of known hymenopteran venom proteins. second, we performed proteomic analyses of crude n. vitripennis venom removed from the venom reservoir, implementing both an off-line two-dimensional liquid chromatography matrix-assisted laser desorption/ io ...

orphan genes are defined as genes that lack detectable similarity to genes in other species and therefore no clear signals of common descent (i.e., homology) can be inferred. orphans are an enigmatic portion of the genome because their origin and function are mostly unknown and they typically make up 10% to 30% of all genes in a genome. several case studies demonstrated that orphans can contribute to lineage-specific adaptation. here, we study orphan genes by comparing 30 arthropod genomes, focu ...

transgenesis of most insects currently relies on fluorescence markers. here we establish a transformation marker system causing phenotypes visible to the naked eye due to changes in the color of melanin pigments, which are widespread in animals. ubiquitous overexpression of arylalkylamine-n-acetyl transferase in the silkworm, bombyx mori, changes the color of newly hatched first-instar larvae from black to a distinctive light brown color, and can be used as a molecular marker by directly connect ...

peroxidasins represent the subfamily 2 of the peroxidase-cyclooxygenase superfamily and are closely related to chordata peroxidases (subfamily 1) and peroxinectins (subfamily 3). they are multidomain proteins containing a heme peroxidase domain with high homology to human lactoperoxidase that mediates one- and two-electron oxidation reactions. additional domains of the secreted and glycosylated metalloproteins are type c-like immunoglobulin domains, typical leucine-rich repeats, as well as a von ...

we investigated a dengue outbreak in dar es salaam, tanzania, in 2014, that was caused by dengue virus (denv) serotype 2. denv infection was present in 101 (20.9%) of 483 patients. patient age and location of residence were associated with infection. seven (4.0%) of 176 patients were co-infected with malaria and denv.

arthropod vectors transmit organisms that cause many emerging and reemerging diseases, and their control is reliant mainly on the use of chemical insecticides. only a few classes of insecticides are available for public health use, and the increased spread of insecticide resistance is a major threat to sustainable disease control. the primary strategy for mitigating the detrimental effects of insecticide resistance is the development of an insecticide resistance management plan. however, few exa ...

many infectious diseases have seasonal outbreaks, which may be driven by cyclical environmental conditions (e.g., an annual rainy season) or human behavior (e.g., school calendars or seasonal migration). if a pathogen is only transmissible for a limited period of time each year, then seasonal outbreaks could infect fewer individuals than expected given the pathogen's in-season transmissibility. influenza, with its short serial interval and long season, probably spreads throughout a population un ...

detection of all four dengue serotypes in aedes aegypti female mosquitoes collected in a rural area in colombia.

the aedes aegypti vector for dengue virus (denv) has been reported in urban and periurban areas. the information about denv circulation in mosquitoes in colombian rural areas is limited, so we aimed to evaluate the presence of denv in ae. aegypti females caught in rural locations of two colombian municipalities, anapoima and la mesa. mosquitoes from 497 rural households in 44 different rural settlements were collected. pools of about 20 ae. aegypti females were processed for denv serotype detect ...

a mosquito sperm's journey from male ejaculate to egg: mechanisms, molecules, and methods for exploration.

the fate of mosquito sperm in the female reproductive tract has been addressed sporadically and incompletely, resulting in significant gaps in our understanding of sperm-female interactions that ultimately lead to fertilization. as with other diptera, mosquito sperm have a complex journey to their ultimate destination, the egg. after copulation, sperm spend a short time at the site of insemination where they are hyperactivated and quickly congregate near the entrance of the spermathecal ducts. w ...

aedes aegypti (diptera: culicidae) has adapted to urban environments; the urbanisation process provides suitable habitats for this disease vector subsequently increasing the probability of the transmission of pathogens in high-density environments. urban environments provide metal stressed larval habitats. however, little is known about the physiological cost of metal stress or how this might affect the performance of this mosquito species. this study aims to characterise the sub-lethal physiolo ...

bacillus thuringiensis cry1a toxins are versatile proteins with multiple modes of action: two distinct pre-pores are involved in toxicity.

cry proteins from bacillus thuringiensis are insecticidal pfts (pore-forming toxins). in the present study, we show that two distinct functional pre-pores of cry1ab are formed after binding of the protoxin or the protease-activated toxin to the cadherin receptor, but before membrane insertion. both pre-pores actively induce pore formation, although with different characteristics, and contribute to the insecticidal activity. we also analysed the oligomerization of the mutant cry1abmod protein. th ...

dengue fever has emerged as a global public health problem in the recent decades. the clinical spectrum of the disease ranges from dengue fever to dengue hemorrhagic fever and dengue shock syndrome. the disease is characterized by increased capillary permeability, thrombocytopenia and coagulopathy. thrombocytopenia with hemorrhagic manifestations warrants platelet transfusions. there is lack of evidence-based guidelines for transfusion support in patients with dengue fever. this contributes to i ...

laboratory evaluation of the development of aedes aegypti in two seasons: influence of different places and different densities.

aedes aegypti is an important vector in brazil being the main vector of the dengue-fever. this paper employs survival curves to describe the time in days from larvae to adult forms of aedes aegypti raised, individually and collectively, and compares it during winter and spring when positioned inside and outside a laboratory. the study was conducted in são vicente, a coastal city in southeastern brazil. the lowest water temperature in winter and in spring was 20 °c and the highest was 26 °c in sp ...

wolbachia naturally infects a wide variety of arthropods, where it plays important roles in host reproduction. it was previously reported that wolbachia did not infect silkworm. by means of pcr and sequencing we found in this study that wolbachia is indeed present in silkworm. phylogenetic analysis indicates that wolbachia infection in silkworm may have occurred via transfer from parasitic wasps. furthermore, southern blotting results suggest a lateral transfer of the wsp gene into the genomes o ...

spatiotemporal distribution of dengue vectors & identification of high risk zones in district sonitpur, assam, india.

dengue is an arboviral disease of public health importance in many parts of india and recently many cases have been reported from northeastern india. aedes mosquitoes, which are the vectors of dengue, are widely prevalent in the region. a study was initiated in sonitpur district of assam to understand the spatiotemporal distribution and seasonal prevalence of dengue vectors and to identify the high risk zones.

forty-one methanol extracts of 28 indigenous medicinal plant species were tested for their insecticidal bioactivity against cotton whitefly, bemisia tabaci (gennadius) (hemiptera: aleyrodidae), adults and second nymphal instars under controlled conditions. this study is within a bioprospection context, in the form of utilizing local plant species as an alternative in sustainable agriculture development. eighteen and nine plant extracts caused a significant decrease in number of live adult and ny ...

arthropod sex ratios can be manipulated by a diverse range of selfish genetic elements, including maternally inherited wolbachia bacteria. feminization by wolbachia is rare but has been described for eurema mandarina butterflies. in this species, some phenotypic and functional females, thought to be zz genetic males, are infected with a feminizing wolbachia strain, wfem. meanwhile, heterogametic wz females are not infected with wfem. here, we establish a quantitative pcr assay allowing reliable ...

how mathematical epidemiology became a field of biology: a commentary on anderson and may (1981) 'the population dynamics of microparasites and their invertebrate hosts'.

we discuss the context, content and importance of the paper 'the population dynamics of microparasites and their invertebrate hosts', by r. m. anderson and r. m. may, published in the philosophical transactions of the royal society as a stand-alone issue in 1981. we do this from the broader perspective of the study of infectious disease dynamics, rather than the specific perspective of the dynamics of insect pathogens. we argue that their 1981 paper fits seamlessly in the systematic study of inf ...

numerous recent studies have illuminated global distributions of human cases of dengue and other mosquito-transmitted diseases, yet the potential distributions of key vector species have not been incorporated integrally into those mapping efforts. projections onto future conditions to illuminate potential distributional shifts in coming decades are similarly lacking, at least outside europe. this study examined the global potential distributions of aedes aegypti and aedes albopictus in relation ...

this article explores four key questions about statistical models developed to describe the recent past and future of vector-borne diseases, with special emphasis on dengue: (1) how many variables should be used to make predictions about the future of vector-borne diseases? (2) is the spatial resolution of a climate dataset an important determinant of model accuracy? (3) does inclusion of the future distributions of vectors affect predictions of the futures of the diseases they transmit? (4) whi ...

present and future projections of habitat suitability of the asian tiger mosquito, a vector of viral pathogens, from global climate simulation.

climate change can influence the transmission of vector-borne diseases (vbds) through altering the habitat suitability of insect vectors. here we present global climate model simulations and evaluate the associated uncertainties in view of the main meteorological factors that may affect the distribution of the asian tiger mosquito (aedes albopictus), which can transmit pathogens that cause chikungunya, dengue fever, yellow fever and various encephalitides. using a general circulation model at 50 ...

after an absence of ≈200 years, chikungunya returned to the american tropics in 2013. the virus is maintained in a complex african zoonotic cycle but escapes into an urban cycle at 40- to 50-year intervals, causing global pandemics. in 1823, classical chikungunya, a viral exanthem in humans, occurred on zanzibar, and in 1827, it arrived in the caribbean and spread to north and south america. in zanzibar, the disease was known as kidenga pepo, swahili for a sudden cramp-like seizure caused by an ...

the olfactory system of drosophila melanogaster provides a powerful model to study molecular and cellular mechanisms underlying function of a sensory system. in the 1970s siddiqi and colleagues pioneered the application of genetics to olfactory research and isolated several mutant drosophila with odorant-specific defects in olfactory behaviour, suggesting that odorants are detected differentially by the olfactory system. since then basic principles of olfactory system function and development ha ...

chile confronts its environmental health future after 25 years of accelerated growth.

chile has recently been reclassified by the world bank from an upper-middle-income country to a high-income country. there has been great progress in the last 20 to 30 years in relation to air and water pollution in chile. yet after 25 years of unrestrained growth, there remain clear challenges posed by air and water pollution, as well as climate change.

chikungunya (chik) fever is a mosquito-borne disease caused by chikungunya virus (chikv). chikungunya infection was first reported from india in 1963 from kolkata. we report the serological and molecular evidence of an outbreak of chikungunya in northeast india that occurred in tura, a hilly and forested terrain in garo hills district of meghalaya.

the changing tails of a novel short interspersed element in aedes aegypti: genomic evidence for slippage retrotransposition and the relationship between 3' tandem repeats and the poly(da) tail.

a novel family of trna-related sines named gecko was discovered in the yellow fever mosquito, aedes aegypti. approximately 7200 copies of gecko were distributed in the a. aegypti genome with a significant bias toward a + t-rich regions. the 3' end of gecko is similar in sequence and identical in secondary structure to the 3' end of mosqui, a non-ltr retrotransposon in a. aegypti. nine conserved substitutions and a deletion separate gecko into two groups. group i includes all gecko that end with ...

bracoviruses contain a large multigene family coding for protein tyrosine phosphatases.

the relationship between parasitic wasps and bracoviruses constitutes one of the few known mutualisms between viruses and eukaryotes. the virions produced in the wasp ovaries are injected into host lepidopteran larvae, where virus genes are expressed, allowing successful development of the parasite by inducing host immune suppression and developmental arrest. bracovirus-bearing wasps have a common phylogenetic origin, and contemporary bracoviruses are hypothesized to have been inherited by chrom ...

it is commonly assumed that a protein must adopt a tertiary structure to achieve its active native state and that regions of a protein that are devoid of alpha-helix or beta-sheet structures are functionally inert. although extended proline-rich regions are recognized as presenting binding motifs to, for example, src homology 2 (sh2) and sh3 domains, the idea persists that natively unfolded regions in functional proteins are simply 'spacers' between the folded domains. such a view has been chall ...

aedes albopictus has replaced aedes aegypti in much of the latter species' historic range within the united states. the leading hypothesis for this displacement is exclusion via resource competition; however, the proximate mechanism producing a competitive advantage for a. albopictus over a. aegypti has not been identified. we performed laboratory experiments to test the hypotheses that these species differ in feeding behavior, and that these differences result in differences in survival when re ...

interactions between pathogens and their insect vectors in nature are under the control of both genetic and non-genetic factors, yet most studies on mosquito vector competence for human pathogens are conducted in laboratory systems that do not consider genetic and/or environmental variability. evaluating the risk of emergence of arthropod-borne viruses (arboviruses) of public health importance such as chikungunya virus (chikv) requires a more realistic appraisal of genetic and environmental cont ...

to study a 2001 dengue fever outbreak in iracoubo, french guiana, we recorded the location of all patients' homes and the date when symptoms were first observed. a geographic information system (gis) was used to integrate the patient-related information. the knox test, a classic space-time analysis technique, was used to detect spatiotemporal clustering. analysis of the relative-risk (rr) variations when space and time distances vary, highlighted the maximum space and time extent of a dengue tra ...

an outbreak of dengue fever occurred among employees of a recreation club in bangladesh. occupational transmission was characterized by a 12% attack rate, no dengue among family contacts, and aedes vectors in club areas. early recognition of the outbreak likely limited its impact.

signature of the oligomeric behaviour of nuclear receptors at the sequence and structural level.

nuclear receptors (nrs) are ligand-dependent transcription factors that control a large number of physiological events through the regulation of gene transcription. nrs function either as homodimers or as heterodimers with retinoid x receptor/ultraspiracle protein (rxr/usp). a structure-based sequence analysis aimed at discovering the molecular mechanism that controls the dimeric association of the ligand-binding domain reveals two sets of differentially conserved residues, which partition the e ...

malaria and dengue fever are endemic in the south-east asian region including india. both the illnesses share similar symptomatology, but differ in certain respects such as different- causative organisms and mosquito vector with diverse habitat. hence, concurrent malaria and dengue fever in the same patient is said to be unusual. there have been cases of concurrent malaria and dengue, but they are scarce from highly endemic region like ours. here, we describe three unusual cases of plasmodium vi ...

functional characterizations of residues arg-158 and tyr-170 of the mosquito-larvicidal bacillus thuringiensis cry4ba.

the insecticidal activity of bacillus thuringiensis (bt) cry toxins involves toxin stabilization, oligomerization, passage across the peritrophic membrane (pm), binding to midgut receptors and pore-formation. the residues arg-158 and tyr-170 have been shown to be crucial for the toxicity of bt cry4ba. we characterized the biological function of these residues. in mosquito larvae, the mutants r158a/e/q (r158) could hardly penetrate the pm due to a significantly reduced ability to alter pm permeab ...

dengue, one of the most common mosquito-borne flavivirus diseases affecting humans, is spread by the aedes aegypti mosquito. most people infected with dengue virus are asymptomatic or only have mild symptoms such as an uncomplicated fever; few have more severe features, while in a small proportion it is life-threatening. severe dengue is defined as that associated with severe bleeding, severe organ dysfunction, or severe plasma leakage. ophthalmic manifestations can involve both the anterior and ...

an expert conference on dengue in africa was held in accra, ghana, in february 2013 to consider key questions regarding the possible expansion of dengue in africa. four key action points were highlighted to advance our understanding of the epidemiology of dengue in africa. first, dengue diagnostic tools must be made more widely available in the healthcare setting in africa. second, representative data need to be collected across africa to uncover the true burden of dengue. third, established net ...

alkaline phosphatase from venom of the endoparasitoid wasp, pteromalus puparum.

using chromogenic substrates 5-bromo-4-chloro-3'-indolyl phosphate and nitro blue tetrazolium, alkaline phosphatase (alpase) was histochemically detected in the venom apparatus of an endoparasitoid wasp, pteromalus puparum l. (hymenoptera: pteromalidae). ultrastructural observations demonstrated its presence in the secretory vesicles and nuclei of the venom gland secretory cells. using p-nitrophenyl phosphate as substrate to measure enzyme activity, the venom alpase was found to be temperature d ...

aphids display extraordinary developmental plasticity in response to environmental cues. these differential responses to environmental changes may be due in part to changes in gene expression patterns. to understand the molecular basis for aphid developmental plasticity, we attempted to identify the chromatin-remodelling machinery in the recently sequenced pea aphid genome. we find that the pea aphid possesses a complement of metazoan histone modifying enzymes with greater gene family diversity ...

comparative analysis of nuclear trna genes of nasonia vitripennis and other arthropods, and relationships to codon usage bias.

using bioinformatics methods, we identified a total of 221 and 199 trna genes in the nuclear genomes of nasonia vitripennis and honey bee (apis mellifera), respectively. we performed comparative analyses of nasonia trna genes with honey bee and other selected insects to understand genomic distribution, sequence evolution and relationship of trna copy number with codon usage patterns. many trna genes are located physically close to each other in the form of small clusters in the nasonia genome. h ...

indiscriminate use of pesticides for the eradication of pests causes tremendous changes to the environment and also to other nontarget organisms. to prevent such contamination of the environment and save nontarget species, zoopesticides are increasingly used as they are cost effective, eco-friendly, safe, and sustainable in the field of agriculture. the present study was undertaken to find out the effect of pygidial secretion (zoopesticide) on odontopus varicornis. the insects were exposed to py ...

functional consequences of mutations in the drosophila histamine receptor hclb.

the gene hclb encodes a histamine-gated chloride channel subunit in drosophila melanogaster. mutations in hclb lead to defects in the visual system and altered sensitivity to the action of ivermectin. to investigate whether this member of the cys-loop receptors is common across the insecta, we analysed the genomes of seven other insect species (diptera, hymenoptera, coleoptera) and revealed orthologues of hclb in all of them. sequence comparisons showed high identity levels between the orthologu ...

the epidemiology of dengue in the americas over the last three decades: a worrisome reality.

we have reported the epidemic patterns of dengue disease in the region of the americas from 1980 through 2007. dengue cases reported to the pan american health organization were analyzed from three periods: 1980-1989 (80s), 1990-1999 (90s), and 2000-2007 (2000-7). age distribution data were examined from brazil, venezuela, honduras, and mexico. cases increased over time: 1,033,417 (80s) to 2,725,405 (90s) to 4,759,007 (2000-7). the highest concentrations were reported in the hispanic caribbean ( ...

cellular mechanisms of acid secretion in the posterior midgut of the larval mosquito (aedes aegypti).

the gut contents of larval mosquitoes are alkalinized by the anterior midgut and reacidified by the posterior midgut. in the present study the cellular mechanisms of reacidification were studied in isolated, perfused posterior midgut by measuring the transepithelial voltage (v(te)) and the rate of acid secretion as indicated by the color change of m-cresol purple during intervals of perfusion stop. the lumen-positive v(te) and reacidification were significantly increased by serotonin (0.2 mumol ...

simultaneous circulation of multiple arboviruses presents diagnostic challenges. in may 2016, chikungunya fever was diagnosed in a traveler from angola to japan. travel history, incubation period, and phylogenetic analysis indicated probable infection acquisition in angola, where a yellow fever outbreak is ongoing. thus, local transmission of chikungunya virus probably also occurs in angola.

detection of wolbachia from field collected aedes albopictus skuse in malaysia.

wolbachia-based vector control strategies have been proposed as a mean to augment the existing measures for controlling dengue vector. prior to utilizing wolbachia in novel vector control strategies, it is crucial to understand the wolbachia-mosquito interactions. many studies have only focused on the prevalence of wolbachia in female aedes albopictus with lack of attention on wolbachia infection on the male ae. albopictus which also affects the effective expression of wolbachia induced- cytopla ...

a comparative analysis of reproductive biology of insect vectors of human disease.

studying the reproductive strategies of insect species that transmit diseases to humans can identify new exploitable targets for the development of vector control methods. here we describe shared characteristics and individual features of the reproductive biology of three major disease vectors: anopheles gambiae, aedes aegypti and glossina morsitans. current studies are identifying i) species-specific molecular cascades that determine female monandrous behavior, ii) core aspects of egg developme ...

we have constructed a genetic linkage map of the edible basidiomycete pleurotus ostreatus (var. florida). the map is based on the segregation of 178 random amplified polymorphic dna and 23 restriction fragment length polymorphism markers; four hydrophobin, two laccase, and two manganese peroxidase genes; both mating type loci; one isozyme locus (est1); the rrna gene sequence; and a repetitive dna sequence in a population of 80 sibling monokaryons. the map identifies 11 linkage groups correspondi ...

the fruit fly drosophila melanogaster was used to examine the mode of action of the novel insecticide and acaricide nodulisporic acid. flies resistant to nodulisporic acid were selected by stepwise increasing the dose of drug in the culture media. the resistant strain, glc(1), is at least 20-fold resistant to nodulisporic acid and 3-fold cross-resistant to the parasiticide ivermectin, and exhibited decreased brood size, decreased locomotion, and bang sensitivity. binding assays using glc(1) head ...

a specific chorion peroxidase is present in aedes aegypti and this enzyme is responsible for catalyzing chorion protein cross-linking through dityrosine formation during chorion hardening. peroxidase-mediated dityrosine cross-linking requires h(2)o(2), and this study discusses the possible involvement of the chorion peroxidase in h(2)o(2) formation by mediating nadh/o(2) oxidoreduction during chorion hardening in a. aegypti eggs. our data show that mosquito chorion peroxidase is able to catalyze ...

molecular characterization of the abp1 5'-flanking region in maize and the teosintes.

auxin-binding protein 1 subsp. mays (abp1) has been suggested as a receptor mediating auxin-induced cell expansion and differentiation. in maize (zea mays), abp1 is encoded by a single gene, abp1. the tata and caat promoter elements as well as the transcriptional start site were previously identified and all were found to be located within a transposable element (te), tourist-zm11. in this study we report the cloning and characterization of the abp1 5'-flanking region in maize and its wild relat ...

a repressible female-specific lethal genetic system for making transgenic insect strains suitable for a sterile-release program.

we have developed a tetracycline-repressible female-specific lethal genetic system in the vinegar fly drosophila melanogaster. one component of the system is the tetracycline-controlled transactivator gene under the control of the fat body and female-specific transcription enhancer from the yolk protein 1 gene. the other component consists of the proapoptotic gene hid under the control of a tetracycline-responsive element. males and females of a strain carrying both components are viable on medi ...

purification and characterization of chorion peroxidase from aedes aegypti eggs.

previous study has shown that a peroxidase is present in the mature eggs of aedes aegypti mosquitoes, and the enzyme is involved in the formation of a rigid and insoluble chorion by catalyzing chorion protein crosslinking through dityrosine formation. in this study, chorion peroxidase was solubilized from egg chorion by 1% sds and 2 m urea and purified by various chromatographic techniques. the enzyme has a relative molecular mass of 63,000 as estimated by sds-page. spectral analysis of the enzy ...

cis and trans factors affecting mos1 mariner evolution and transposition in vitro, and its potential for functional genomics.

mos1 and other mariner / tc1 transposons move horizon-tally during evolution, and when transplanted into heterologous species can transpose in organisms ranging from prokaryotes to protozoans and vertebrates. to further develop the drosophila mos1 mariner system as a genetic tool and to probe mechanisms affecting the regulation of transposition activity, we developed an in vitro system for mos1 transposition using purified transposase and selectable mos1 derivatives. transposition frequencies of ...

recent, extensive, and preferential insertion of members of the miniature inverted-repeat transposable element family heartbreaker into genic regions of maize.

a 314-bp dna element called heartbreaker-hm1 (hbr-hm1) was previously identified in the 3' untranslated region of a mutant allele of the maize disease resistance gene hm1. this element has structural features of miniature inverted-repeat transposable elements (mites) and is a member of a large family of approximately 4,000 copies in the maize genome. unlike previously described mites, most members of the hbr family display over 90% sequence identity. this, coupled with the insertion of an hbr el ...

regulation of the vitellogenin receptor during drosophila melanogaster oogenesis.

in many insects, development of the oocyte arrests temporarily just before vitellogenesis, the period when vitellogenins (yolk proteins) accumulate in the oocyte. following hormonal and environmental cues, development of the oocyte resumes, and endocytosis of vitellogenins begins. an essential component of yolk uptake is the vitellogenin receptor. in this report, we describe the ovarian expression pattern and subcellular localization of the mrna and protein encoded by the drosophila melanogaster ...

the caenorhabditis elegans oocyte is a highly amenable system for forward and reverse genetic analysis of receptor-mediated endocytosis. we describe the use of transgenic strains expressing a vitellogenin::green fluorescent protein (yp170::gfp) fusion to monitor yolk endocytosis by the c. elegans oocyte in vivo. this yp170::gfp reporter was used to assay the functions of c. elegans predicted proteins homologous to vertebrate endocytosis factors using rna-mediated interference. we show that the b ...

in a bid to reduce the risk of dengue fever in parts of vietnam, the australian foundation for the peoples of asia and the pacific, an aid organization, recently completed a 3-year program using the mesocyclops crustacean, an organism about 1 mm long which eats the larvae of mosquitos which transmit dengue fever. the program appears to eradicated the larvae from the northern vietnamese province of phan boi, and there was a 75% success rate in other provinces. the queensland institute of medical ...

toxicity of certain penta-coordinated organotin(iv) and tetra-coordinated tin(ii) complexes of heterocyclic beta-diketones against the larvae of aedes aegypti (liston).

some organotin(iv) and tin(ii) complexes of composition r(3)sn[r'coc:con(c(6)h(5))n:cch(3)] (where r=c(4)h(9), r'=ch(3), c(3)h(5), p-clc(6)h(4); r=c(6)h(5), r'=c(6)h(5) and p-clc(6)h(4)) and sn[p-clc(6)h(4)coc:con(c(6)h(5))n:cch(3)](2) were screened for their toxicity against aedes aegypti larvae. organotin(iv) complexes were more active than tin(ii) complexes.

the piggybac (ifp2) short inverted terminal repeat transposable element from the cabbage looper trichoplusia ni was tested for gene transfer vector function as part of a bipartite vector-helper system in the mediterranean fruit fly ceratitis capitata. a piggybac vector marked with the medfly white gene was tested with a normally regulated piggybac transposase helper at two different concentrations in a white eye host strain. both experiments yielded transformants at an approximate frequency of 3 ...

the mariner transposable element is capable of interplasmid transposition in the embryonic soma of the yellow fever mosquito, aedes aegypti. to determine if this demonstrated mobility could be utilized to genetically transform the mosquito, a modified mariner element marked with a wild-type allele of the drosophila melanogaster cinnabar gene was microinjected into embryos of a kynurenine hydroxylase-deficient, white-eyed recipient strain. three of 69 fertile male founders resulting from the micr ...

mosquito transferrin, an acute-phase protein that is up-regulated upon infection.

when treated with heat-killed bacterial cells, mosquito cells in culture respond by up-regulating several proteins. among these is a 66-kda protein (p66) that is secreted from cells derived from both aedes aegypti and aedes albopictus. p66 was degraded by proteolysis and gave a virtually identical pattern of peptide products for each mosquito species. the sequence of one peptide (31 amino acids) was determined and found to have similarity to insect transferrins. by using conserved regions of ins ...

a tremendous wealth of data is accumulating on the variety and distribution of transposable elements (tes) in natural populations. there is little doubt that tes provide new genetic variation on a scale, and with a degree of sophistication, previously unimagined. there are many examples of mutations and other types of genetic variation associated with the activity of mobile elements. mutant phenotypes range from subtle changes in tissue specificity to dramatic alterations in the development and ...

the use of random amplified polymorphic dna from the polymerase chain reaction (rapd-pcr) allows efficient construction of saturated linkage maps. however, when analyzed by agarose gel electrophoresis, most rapd-pcr markers segregate as dominant alleles, reducing the amount of linkage information obtained. we describe the use of single strand conformation polymorphism (sscp) analysis of rapd markers to generate linkage maps in a haplodiploid parasitic wasp bracon (habrobracon) hebetor and a dipl ...

subunit cleavage of mosquito pro-vitellogenin by a subtilisin-like convertase.

the eukaryotic convertase family plays an important role in posttranslational proteolytic processing and activation of many pro- and polypeptides that have at their cleavage sites the paired basic motif, rx(k/r)r. recent studies have revealed that the cleavage site of insect pro-vitellogenins (pro-vg) also contains this motif. to identify and characterize the insect pro-vg processing enzyme, vg convertase (vc), its cdna was cloned from a vitellogenic female fat body cdna library of the mosquito, ...

to study dengue vector breeding patterns under a variety of conditions in public and private spaces; to explore the ecological, biological and social (eco-bio-social) factors involved in vector breeding and viral transmission, and to define the main implications for vector control.

in most insect species, juvenile hormones regulate critical physiological processes such as metamorphosis and reproduction. in insects, these sesquiterpenoids are synthesized by retrocerebral endocrine organs, the corpora allata, via the classical mevalonate (mva) pathway. one of these compounds, juvenile hormone iii (jh iii), has also been identified in the sedge cyperus iria. in higher plants, biosynthesis of the sesquiterpenoid backbone may proceed through two distinct pathways: the mva pathw ...

an intensive linkage map of the yellow fever mosquito, aedes aegypti, was constructed using single-strand conformation polymorphism (sscp) analysis of cdna markers to identify single nucleotide polymorphisms (snps). a total of 94 a. aegypti cdnas were downloaded from genbank and primers were designed to amplify fragments <500 bp in size. these primer pairs amplified 94 loci, 57 (61%) of which segregated in a single f(1) intercross family among 83 f(2) progeny. this allowed us to produce a dense ...

two approaches were used to correlate the aedes aegypti genetic linkage map to the physical map. sts markers were developed for previously mapped rflp-based genetic markers so that large genomic clones from cosmid libraries could be found and placed to the metaphase chromosome physical maps using standard fish methods. eight cosmids were identified that contained eight rflp marker sequences, and these cosmids were located on the metaphase chromosomes. twenty-one cdnas were mapped directly to met ...

our growing comprehension of the biological roles of glycan moieties has created a clear need for expression systems that can produce mammalian-type glycoproteins. in turn, this has intensified interest in understanding the protein glycosylation pathways of the heterologous hosts that are commonly used for recombinant glycoprotein expression. among these, insect cells are the most widely used and, particularly in their role as hosts for baculovirus expression vectors, provide a powerful tool for ...

dengue viral infection has rapidly spread around the world in recent decades. in korea, autochthonous cases of dengue fever have not been confirmed yet. however, imported dengue cases have been increased since 2001. the risk of developing severe dengue in korean has been increased by the accumulation of past-infected persons with residual antibodies to dengue virus and the remarkable growth of traveling to endemic countries in southeast asia. notably, most of imported dengue cases were identifie ...

accelerated evolution of constraint elements for hematophagic adaptation in mosquitoes.

comparative genomics is a powerful approach that comprehensively interprets the genome. herein, we performed whole genome comparative analysis of 16 diptera genomes, including four mosquitoes and 12 drosophilae. we found more than 540 000 constraint elements (ces) in the diptera genome, with the majority found in the intergenic, coding and intronic regions. accelerated elements (aes) identified in mosquitoes were mostly in the protein-coding regions (>93%), which differs from vertebrates in geno ...

dengue is one of the most important vector-borne disease and an increasing problem worldwide because of current globalization trends. roughly, half the world's population lives in dengue endemic countries, and nearly 100 million people are infected annually with dengue. india has the highest burden of the disease with 34% of the global cases. in the context of an expanding and potentially fatal infectious disease without effective prevention or specific treatment, the public health value of a pr ...

we identified 78 imported chikungunya cases in taiwan during 2006-2014. sixty-six (84.6%) cases were initially suspected to be dengue, which indicates the necessity for laboratory diagnostics in differentiation between dengue and chikungunya. results also emphasize the need for active surveillance of febrile illness at points of entry.

releasing mosquitoes infected with the intracellular bacteria wolbachia is a candidate strategy for dengue control that has recently advanced to field-testing. a critical next step is to evaluate the impact of this strategy on dengue epidemiology. a recent study by ferguson and colleagues presents a mathematical framework to predict the likely effect of mosquitoes carrying wolbachia on dengue virus transmission. fitting the mathematical model to empirical data obtained with wolbachia-infected mo ...

females of the hematophagous mosquito species require a vertebrate blood meal to supply amino acids and other nutrients necessary for egg development, serving as the driving force for the spread of many vector-borne diseases in humans. blood digestion utilizes both early and late phase serine proteases (sps) that are differentially regulated at the transcriptional and post-transcriptional level. to uncover the regulatory complexity of sps in the female mosquito midgut, we investigated involvemen ...

hearing is a specialized mechanosensory modality that is refined during evolution to meet the particular requirements of different organisms. in the fruitfly, drosophila, hearing is mediated by johnston's organ, a large chordotonal organ in the antenna that is exquisitely sensitive to the near-field acoustic signal of courtship songs generated by male wing vibration. we summarize recent progress in understanding the molecular genetic determinants of johnston's organ development and discuss surpr ...

transposable elements are mobile genetic units that exhibit broad diversity in their structure and transposition mechanisms. transposable elements occupy a large fraction of many eukaryotic genomes and their movement and accumulation represent a major force shaping the genes and genomes of almost all organisms. this review focuses on dna-mediated or class 2 transposons and emphasizes how this class of elements is distinguished from other types of mobile elements in terms of their structure, ampl ...